The present invention relates to a cartridge for the preparation of beverages and, in particular, to sealed cartridges which are formed from substantially air- and water-impermeable materials and which contain one or more ingredients for the preparation of beverages.
It has previously been proposed to seal beverage preparation ingredients in individual air-impermeable packages. For example, cartridges or capsules containing compacted ground coffee are known for use in certain coffee preparation machines which are generally termed “espresso” machines. In the production of coffee using these preparation machines the coffee cartridge is placed in a brewing chamber and hot water is passed though the cartridge at relatively high pressures, thereby extracting the aromatic coffee constituents from the ground coffee to produce the coffee beverage. Typically, such machines operate at a pressure of greater than 6×105 Pa. The preparation machines of the type described have to date been relatively expensive since components of the machine, such as the water pumps and seals, must be able to withstand the high pressures.
In WO01/58786 there is described a cartridge for the preparation of beverages which operates at a pressure generally in the range 0.7 to 2.0×105 Pa. However, the cartridge is designed for use in a beverage preparation machine for the commercial or industrial market and is relatively expensive. Hence, there remains a requirement for a cartridge for the preparation of beverages wherein the cartridges and beverage preparation machine are suitable, in particular, for the domestic market in terms of cost, performance and reliability.
In typical known beverage cartridges the inlet and outlet of the beverage cartridges are formed on opposite sides of the cartridge. This has the disadvantage that the beverage preparation machine used to dispense the cartridges normally requires a complicated mechanical arrangement for moving inlet and outlet piercers into engagement with the cartridge from opposite directions. In addition, the inlet and outlet piercers can also impede access for inserting and withdrawing the beverage cartridge from the beverage preparation machine. In WO01/60220 a beverage cartridge is provided wherein the inlet and outlet are formed on the same side of the cartridge. However, this cartridge can be prone to blockage of the inlet piercers since they contact directly the beverage ingredients.